Supplement
Urolithin A
Urolithin A is a gut-microbiome metabolite of pomegranate compounds, developed commercially as a mitophagy activator. It is one of the more seriously researched new longevity supplements — real randomised trials with pre-registered endpoints — and also a case study in how far commercial science still is from health outcomes: the trials measure molecular signatures and muscle endurance, and nearly all of them are run by the company that sells it.
Quick verdict
Randomised trials show improved mitochondrial biomarkers, and one trial in older adults reported better muscle endurance on some measures while missing its primary walking endpoint. All key trials are funded by the manufacturer. No health-outcome or lifespan evidence exists.
The assessment
Claim by claim
Each claim is graded on its own evidence. A grade for one claim says nothing about the others.
| Claim | What was measured | Evidence |
|---|---|---|
| Improves muscle endurance in older adults | Physical function | Early |
| Improves biomarkers of mitochondrial health | Surrogate biomarker | Early |
Improves muscle endurance in older adults
Early human evidenceOutcome measured: Physical function — A measured capability such as walking speed, grip strength or VO₂ max.
A randomised trial in 66 older adults reported improved muscle endurance in hand and leg muscle tests after four months — while the primary endpoint, six-minute walking distance, did not beat placebo. Encouraging and honest to describe as early: the positive findings were secondary measures.
Why this grade — the appraisal in full
One or a small number of small, short or preliminary human studies. Directionally interesting, not yet dependable.
- Strongest study design. Randomised controlled trial with 66 participants.
- Human research volume. 1 human study, 66 participants in total.
- What was measured. 1 human study measured a clinical or functional outcome rather than a laboratory marker alone.
- Replication. The supporting result has not been independently replicated in humans.
- Study duration. Longest human study ran 17 weeks.
- Funding and conflicts. 1 of 1 human studies were funded by, or authored by, a party with a commercial interest in the result.
Limitations. Primary endpoint missed; manufacturer-funded; single trial in this population.
| Study | Design | Population | Finding |
|---|---|---|---|
| [1]Effect of Urolithin A Supplementation on Muscle Endurance and Mitochondrial Heal…JAMA network open · 2022 · PMID 35050355 | Randomised controlled trialHuman | 66 participantsHealthy participants | Supports the claimImproved muscle endurance on secondary measures; primary six-minute-walk endpoint not significant. Manufacturer-funded. |
Improves biomarkers of mitochondrial health
Early human evidenceOutcome measured: Surrogate biomarker — A laboratory marker measured as a stand-in for health. A change here does not by itself demonstrate a health benefit.
The first-in-human randomised study found urolithin A safe and reported a molecular signature of improved mitochondrial and cellular health in muscle tissue. This is the claim the product is actually built on — a biomarker change, upstream of any demonstrated benefit.
Why this grade — the appraisal in full
One or a small number of small, short or preliminary human studies. Directionally interesting, not yet dependable.
- Strongest study design. Randomised controlled trial.
- Human research volume. 1 human study, 0 participants in total.
- What was measured. Human studies measured surrogate biomarkers only. A change in a marker is not by itself a demonstrated health benefit.
- Replication. The supporting result has not been independently replicated in humans.
- Study duration. Longest human study ran 4 weeks — too short to show durable effects.
- Funding and conflicts. 1 of 1 human studies were funded by, or authored by, a party with a commercial interest in the result.
Limitations. Molecular endpoints only; manufacturer-run; whether the signature translates into anything a person would notice is untested.
| Study | Design | Population | Finding |
|---|---|---|---|
| [2]The mitophagy activator urolithin A is safe and induces a molecular signature of…Nature metabolism · 2019 · PMID 32694802 | Randomised controlled trialHuman | Size not recordedHealthy participants | Supports the claimFirst-in-human: safe; molecular signature of improved mitochondrial health in skeletal muscle. Manufacturer-run. |
Human evidence
2 studies in people.
- [1]Randomised controlled trial · 66 participants
- [2]Randomised controlled trial
Animal and laboratory evidence
Shown separately, and never used to support a human claim.
No preclinical study is currently linked on this page.
Before anything else
Safety and interactions
Well tolerated in trials to date at studied doses; long-term data beyond trial durations are limited.
The ledger
Grade history
22 August 2026
First published appraisal of this claim. Study links added: PMID 35050355.
22 August 2026
First published appraisal of this claim. Study links added: PMID 32694802.
Falsifiability
What would change our view
Independent replication outside manufacturer funding, and any trial connecting the biomarker changes to a functional or health outcome that reaches its primary endpoint.
Check everything
Sources
Every citation links to its PubMed record. Bibliographic details are retrieved from PubMed, not written by us.
- [1]Effect of Urolithin A Supplementation on Muscle Endurance and Mitochondrial Health in Older Adults: A Randomized Clinical Trial Liu S et al.. JAMA network open. 2022. PMID 35050355 · doi:10.1001/jamanetworkopen.2021.44279
- [2]The mitophagy activator urolithin A is safe and induces a molecular signature of improved mitochondrial and cellular health in humans Andreux PA et al.. Nature metabolism. 2019. PMID 32694802 · doi:10.1038/s42255-019-0073-4